Buggy code:
public class PlayerVars { public static void addVars ( ) { } private static class GroupVar extends Var { @ Keys ( keys = { "group" , "g" } ) public String getValue ( UUID uuid ) { Player player = ServerUtil . getPlayer ( uuid ) ; if ( player != null ) { return Reader . getRawGroup ( uuid , player . getWorld ( ) . getName ( ) ) ; } return "" ; } } private static class PrefixVar extends Var { @ Keys ( keys = { "prefix" , "p" } ) public String getValue ( UUID uuid ) { Player player = ServerUtil . getPlayer ( uuid ) ; if ( player != null ) { return Reader . getRawPrefix ( uuid , player . getWorld ( ) . getName ( ) ) ; } return "" ; } } private static class SuffixVar extends Var { @ Keys ( keys = { "suffix" , "s" } ) public String getValue ( UUID uuid ) { Player player = ServerUtil . getPlayer ( uuid ) ; if ( player != null ) { return Reader . getRawSuffix ( uuid , player . getWorld ( ) . getName ( ) ) ; } return "" ; } } private static class MNameVar extends Var { @ Keys ( keys = { "mname" , "mn" } ) public String getValue ( UUID uuid ) { Player player = ServerUtil . getPlayer ( uuid ) ; if ( player != null ) { return Reader . getMName ( uuid ) ; } return "" ; } } private static class PNameVar extends Var { @ Keys ( keys = { "pname" , "n" } ) public String getValue ( UUID uuid ) { Player player = ServerUtil . getPlayer ( uuid ) ; if ( player != null ) { return player . getName ( ) ; } return "" ; } } private static class DNameVar extends Var { @ Keys ( keys = { "displayname" , "dname" , "dn" } ) public String getValue ( UUID uuid ) { Player player = ServerUtil . getPlayer ( uuid ) ; if ( player != null ) { <START_BUG> return player . getCustomName ( ) ; <END_BUG> } return "" ; } } private static class ExpVar extends Var { @ Keys ( keys = { "experience" , "exp" } ) public String getValue ( UUID uuid ) { Player player = ServerUtil . getPlayer ( uuid ) ; if ( player != null ) { return String . valueOf ( 0 ) ; } return "" ; } } private static class ExpBarVar extends Var { @ Keys ( keys = { "experiencebar" , "expb" , "ebar" } ) public String getValue ( UUID uuid ) { Player player = ServerUtil . getPlayer ( uuid ) ; if ( player != null ) { return API . createBasicBar ( 0 , 10 , 10 ) ; } return "" ; } } private static class GameModeVar extends Var { @ Keys ( keys = { "gamemode" , "gm" } ) public String getValue ( UUID uuid ) { Player player = ServerUtil . getPlayer ( uuid ) ; if ( player != null ) { return String . valueOf ( "" ) ; } return "" ; } } private static class HealthVar extends Var { @ Keys ( keys = { "health" , "h" } ) public String getValue ( UUID uuid ) { Player player = ServerUtil . getPlayer ( uuid ) ; if ( player != null ) { return String . valueOf ( player . getHealth ( ) ) ; } return "" ; } } private static class HealthBarVar extends Var { @ Keys ( keys = { "healthbar" , "hb" } ) public String getValue ( UUID uuid ) { Player player = ServerUtil . getPlayer ( uuid ) ; if ( player != null ) { return API . createHealthBar ( player ) ; } return "" ; } } private static class HungerVar extends Var { @ Keys ( keys = { "hunger" } ) public String getValue ( UUID uuid ) { Player player = ServerUtil . getPlayer ( uuid ) ; if ( player != null ) { return String . valueOf ( player . getHunger ( ) ) ; } return "" ; } } private static class HungerBarVar extends Var { @ Keys ( keys = { "hungerbar" , "hub" } ) public String getValue ( UUID uuid ) { Player player = ServerUtil . getPlayer ( uuid ) ; if ( player != null ) { return API . createBasicBar ( player . getHunger ( ) , 20 , 10 ) ; } return "" ; } } private static class LevelVar extends Var { @ Keys ( keys = { "level" , "l" } ) public String getValue ( UUID uuid ) { Player player = ServerUtil . getPlayer ( uuid ) ; if ( player != null ) { return String . valueOf ( "" ) ; } return "" ; } } private static class LocVar extends Var { @ Keys ( keys = { "location" , "loc" } ) public String getValue ( UUID uuid ) { Player player = ServerUtil . getPlayer ( uuid ) ; if ( player != null ) { return ( ( ( ( ( ( "X:<seq2seq4repair_space>" + ( player . getLocation ( ) . getPosition ( ) . getX ( ) ) ) + ",<seq2seq4repair_space>" ) + "Y:<seq2seq4repair_space>" ) + ( player . getLocation ( ) . getPosition ( ) . getY ( ) ) ) + ",<seq2seq4repair_space>" ) + "Z:<seq2seq4repair_space>" ) + ( player . getLocation ( ) . getPosition ( ) . getZ ( ) ) ; } return "" ; } }

Fix:
return player . getDisplayName ( ) . getContent ( ) . toString ( ) ;